Melanoseris lineage

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Melanoseris lineage

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Common names

Chinese (China): 毛鳞菊属 mao lin ju shuA

Systematics

The name Melanoseris, established by Decaisne in 1843 (see Synonymy) to include two species from the Himalayas, which are now treated as a single species of wider distribution in the Himalayas, M. lessertiana, is one of the oldest generic names in the subtribe Lactucinae. The genus was considered by Decaisne to differ from Cicerbita (at that time treated under the name Mulgedium) because of its beaked achenes and from Lactuca, because of its pappus with an outer series of minute hairs. Edgeworth (1846) subsequently added a few more Himalayan species, which recently have been confirmed to be related (Wang & al. 2013), but afterwards the name was fallen into oblivion.

The name, typified by Melanoseris lessertiana (see Synonymy), was only recently revived by Shih & Kilian (in Shih & al. 2011), based on an initial, then still unpublished ITS phylogeny through which it became evident that the types of the newly established genera Chaetoseris and Stenoseris by Shih (1991) as well as a number of species formerly placed in Cephalorrhynchus, Cicerbita, Lactuca, Mulgedium and Prenanthes are all members of a sizable Melanoseris clade.

The extensive molecular phylogenetic analyses by Wang & al. (2013) and Kilian & al. (2017), based on both nuclear and plastid markers, clearly confirm the Melanoseris lineage. This lineage unites the Sino-Himalayan genera Chaetoseris and Stenoseris with a number of species of the same region formerly asigned to genera such as Prenanthes, Mulgedium, Cephalorrhynchus, Cicerbita and Lactuca.

The monospecific near-endemic Chinese genus Parasyncalathium (Zhang & al. 2011[a]) is also deeply nested in the Melanoseris lineage. This last genus accommodated the species originally described as Lactuca souliei. That species orginally was placed together with habitually similar species in Lactuca sect. Aggregatae, which later became the separate genus Syncalathium. Recent works by Zhang & al. (2007), Kilian & al. (2009: 348–350) and Zhang & al. (2011[a,b]) corroborated the observation by Stebbins (1940: 47–50), inferred from achene morphology, that the species is entirely misplaced in Syncalathium and the Crepidinae and that its striking overall similarity to the species of Syncalathium is purely a result of convergent evolution in response to the environmental changes following the uplift of the Qinghai-Xizang Plateau.

Besides Sino-Himalayan species, which, as far as known, are diploid with a chromosome number of 2n = 16 (Wang & al. 2013), Melanoseris also includes S, SE (extending to Sumatra and Java), SW and Central Asian as well as tropical African species (Kilian & al. 2017).

Melanoseris forms besides Lactuca the largest lineage of the Lactucinae and is at the same time a morphologically fairly diverse one. Its habits range from low rosette herbs to tall forbs and climbers, flower numbers per capitulum from 3 to c. 40 and achenes from truncate to long-rostrate. Taxonomically difficult assemblages in certain portions of the genus seem to have been caused by hybridisation and reticulate evolution (Wang & al. 2013).

Morphological differentiation in particular from Lactuca but also from other lineages is shallow or perhaps absent, and the molecular analyses indicate that reticulation between Lactuca and Melanoseris may have occurred (Kilian & al. 2017).

References


Edgeworth M. P. 1846: Descriptions of some unpublished species of plants from North-Western India. – Trans. Linn. Soc. London 20: 23–91.

Kilian N., Gemeinholzer B. & Lack H. W. 2009: Tribe Cichorieae. – Pp. 343–383 In: Funk V. A., Susanna A., Stuessy T. & Bayer R. (ed.), Systematics, evolution, and biogeography of the Compositae. – Vienna: IAPT

Kilian N., Sennikov A., Wang Z.-H., Gemeinholzer B. & Zhang J.-W. 2017[a]: Sub-Paratethyan origin and Middle to Late Miocene principal diversification of the Lactucinae (Cichorieae, Compositae) inferred from molecular phylogenetics, divergence-dating and biogeographic analysis. – Taxon 66: 675-703. // ➪ //

Shih C. 1991: On circumscription of the genus Cicerbita Wall., and two new genera of Compositae from Sino-Himalayan region. – Acta Phytotax. Sin. 29: 394–417.

Shih C., Ge X. J.; Kilian N., Kirschner J., Štěpánek J., Sukhorukov A. P., Mavrodiev E. V. & Gottschlich G. 2011: Cichorieae. – Pp. 195–353 in: Wu Z. Y., Raven P. H. & Hong D. Y. (ed.), Flora of China 20–21. Asteraceae. – Beijing: Science Press & St Louis: Missouri Botanical Garden. // ➪ //

Stebbins G. L. 1940: Studies in Cichorieae: Dubyaea and Soroseris. Endemics of the Sino-Himalayan region. – Mem. Torrey Bot. Club 19(3): 1–76.

Wang Z.-H., Peng H. & Kilian N. 2013: Molecular phylogeny of the Lactuca alliance (Cichorieae subtribe Lactucinae, Asteraceae) with focus on their Chinese centre of diversity detects potential events of reticulation and chloroplast capture. – PLoS ONE 8(12): e82692. // ➪ //

Zhang, J.-W., Boufford D. E.& Sun H. 2011[a]: Parasyncalathium J.W. Zhang, Boufford & H. Sun (Asteraceae, Cichorieae): A new genus endemic to the Himalaya-Hengduan Mountains. – Taxon 60: 1678–1684.

Zhang J.-W., Sun H. & Nie E.-L. 2007: Karyological studies on the Sino-Himalayan endemic Soroseris and two related genera of tribe Lactuceae (Asteraceae). – Bot. J. Linn. Soc. 154: 79–87.

Zhang J.-W., Nie Z. N., Wen J. & Sun H. 2011[b]: Molecular phylogeny and biogeography of three closely related genera, Soroseris, Stebbinsia, and Syncalathium (Asteraceae, Cichorieae), endemic to the Tibetan Plateau, SW China. – Taxon 60: 15–26.

Description

Herbs, perennial, sometimes rosulate, rarely acaulescent, glabrous, glandular hairy, pilose, or hispid. Stems solitary or several, usually leafy. Leaves pinnate, lyrately pinnate, or undivided. Capitula often nodding, with 3–40 florets. Involucre narrowly cylindric to broadly campanulate. Phyllaries glabrous or with soft or rigid hairs; outer phyllaries mostly in several series, gradually longer centripetally, mostly to more than 1/2 as long as inner ones and often even ± approaching them in length, more rarely very short, absent in one species with a secondary capitulum (Melanoseris souliei); inner phyllaries 3 to many, ± equal in length, ± linearlanceolate to linear. Receptacle naked. Florets bluish, purplish, sometimes yellow, or rarely white. Achene some shade of brown, mostly ellipsoid and strongly compressed, more rarely subcylindric to ± fusiform and weakly compressed, with (4 or)5 main ribs (2 mostly strongly broadened lateral, 1 median ventrally, and (1 or)2 median dorsally) and with 0–2 slender ribs in between main ribs, apex truncate, attenuate, or with a stout beak. Pappus white or rarely yellowish, single of slender scabrid bristles or more frequently double and with an additional outer row of minute hairs.

from: Shih C. & Kilian N. in Wu Z. Y. & al. (ed.), Flora of China 20–21: 217. 2011, Beijing & St Louis.

Chromosome numbers

Diploids and, rarely, tetraploids, x = 9, 8.B

Bibliography

A. Wu & al., Flora of China 20-21. 2011 (as Melanoseris Decne.)
B. Kilian N., Sennikov A. N., Wang Z. H. & al., Sub-Paratethyan origin and Middle to Late Miocene principal diversification of the Lactucinae (Cichorieae, Compositae) inferred from molecular phylogenetics, divergence-dating and biogeographic analysis in Taxon 66: 675-703. 2017